


Jump the Shark

by firefright, Skalidra



Category: Batman - All Media Types, DCU (Comics)
Genre: Alternate Universe - Merpeople, Ambiguous/Open Ending, Blood and Violence, Claiming Bites, Extremely Dubious Consent, M/M, Mating Rituals, No more serious titles; we die like men with our puns, Plot What Plot/Porn Without Plot, Rape/Non-con Elements
Language: English
Status: Completed
Published: 2019-04-28
Updated: 2019-04-28
Packaged: 2020-02-09 11:07:33
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 4,978
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/18636904
Author URL: https://archiveofourown.org/users/firefright/pseuds/firefright, https://archiveofourown.org/users/Skalidra/pseuds/Skalidra
Summary: Dick and Jason have been dancing around each other for months, deciding whether or not to bond. But now, finally on the cusp of making that decision, they're about to discover they're not the only ones who have been considering it, and that the other mer who's been watching them is not one to take no for an answer.





	Jump the Shark

**Author's Note:**

> Hi all, here's a thing we wrote for the [SladeRobin Mini Event](https://sladerobinweek.tumblr.com/) over on tumblr and just about finished it in the nick of time. As you can probably guess from the tags, the prompts we decided to use are 'Mer AU' and 'Forced Bonding'. Hope you enjoy!

They’re still entwined together when the shadow passes over them, casting darkness on the warm sandy bottom of the sea floor. Jason shivers reflexively, even though the actual temperature of the water doesn’t change because of it. A second later, he feels Dick’s arm and tail tighten around him, as his suitor bends his head head down to nuzzle his neck over the bite mark he left there barely an hour before.

“You okay?”

“Yeah,” he murmurs softly, casting a look upwards past the walls of coral around them to the far above surface of the sea, “Fine.” Jason frowns, “I just thought…”

“Thought what?” Dick asks him curiously.

“Nothing,” he sighs, “Probably just a big fish or something.”

“Hm.” Dick looks up as well, then shrugs before kissing at Jason’s shoulder. “Probably.” His hand wanders a little lower, down Jason’s stomach, and Jason feels him smirk against his skin as he uses his fingers to tease the edges of his slit. “Whatever it was, looks like it’s gone now.”

“Dick,” Jason groans at the touch. He tightens his tail around Dick’s in return, biting his lip at the feeling, “Are you really…”

“Don’t you want to go again?” Dick purrs, “I know I do.”

“It’s barely been an hour.”

“So?” Dick kisses his neck, pushing one finger between the still slick and slightly sore lips of Jason’s opening. “I can’t stop thinking about how good you felt. Want to be in you all the time, Jay. Want to fuck you, claim you; want to see you all fat with our children and—”

Jason snorts, blushing deep even as he pushes his hips forward in an attempt to get that finger deeper inside. “Getting a little ahead of yourself, aren’t you?”

“Why not?” Dick replies cheekily, nipping under his ear now. “Considering what we just did and all...”

“We had sex,” Jason flushes, “That doesn’t mean I’ve agreed to be your mate, yet.”

Dick chuckles deeply, “True. I guess that just means I’ll have to work on persuading you a little more.”

He turns his head, and they spend the next few minutes kissing as Dick works his fingers inside Jason. He’s still easy and loose for him, eager to go again as well despite his grousing, and Jason groans when he feels Dick’s shaft extend against his back, rubbing over the bumps of his spine. “Dick…”

“Roll over,” Dick commands him, loosening the hold of his tail and withdrawing his fingers to give Jason room to do so. “Roll over, little—” Then he freezes, looks up, startled by the sight of something over the top of Jason’s head. Jason opens his mouth to ask what it is, but before he can Dick is suddenly hissing, deep and low, the sound beyond threatening as his teeth and claws extend and with an almighty thrust of his tail he suddenly pushes himself off of Jason; driving forwards to whatever it is he’s seen.

Twisting in the sand, Jason rolls himself into a position where he can look too, and what he sees sends a chill down his spine just as much as the much longer, deeper, answering hiss to Dick’s own that fills the currents around them does. The mer his suitor is now attacking is _huge_. Big, pale, and scarred, with white hair and distinctive fins. Stripes run in a primal pattern down his tail, and all Jason has time to think is _shark_ before instinct takes over and he too launches himself forward to help Dick fight.

Blood already clouds the water when he reaches them, amidst a haze of stirred up sand. Jason unleashes his own claws and slams into the strange mer just as he throws Dick into the nearest wall of coral, ripping and tearing into his flesh as best he can while making his outrage at the intrusion known with high-pitched warning shrieks.

The strange mer answers with another hiss. When he cuffs Jason across the head, it feels like he slammed his skull into the side of a sea cliff. A second blow follows, but this time Jason is more prepared, latching his claws into the offending arm and then holding on tight as he brings his tail round to slam into the mer’s back.

Despite the strength Jason puts into the blow, it barely seems to stagger the shark, who grabs him by the scruff of his neck with his free hand and yanks Jason’s head up. He gets a brief glimpse of a scarred face and the empty socket of the mer’s right eye before teeth are sinking into his shoulder. The sound of Dick’s furious scream behind him is the loudest noise above the crunch of his own bone.

“ _Down_ ,” is the first real word the mer says to him, with Jason’s blood staining his teeth. Jason is stunned as he’s thrown back, claws torn free from the mer’s arm before the shark is twisting, turning to meet Dick’s renewed charge.

There’s so much blood and sand in the water now he can barely make out any of what’s going on. Jason bites back a whimper as he clamps a hand over the missing chunk of his shoulder, struggling to pull himself back together to fight again. He can taste his and Dick’s blood on his tongue, as well as a third, far more unfamiliar flavour.

From inside the cloud there’s a sudden crack of coral breaking, and then a huge shape appears swimming towards him. Jason’s eyes widen at the sight of the shark mer dragging Dick’s unconscious and helplessly floating body behind him.

“You son of a—!” he launches himself forward again, ignoring the terrible pain in his shoulder. 

The shark anticipates his move, though, letting go of Dick and — with a seemingly effortless sweep of his tail despite the numerous bloody cuts decorating his body — sending Jason spinning back once again. His back hits the reef and he howls in pain, a second before a heavy weight suddenly slams on top of him.

“I told you to stay down, boy.”

Jason hisses, baring his teeth at that hard face. Lifting his hands, he aims to claw it before his wrists are suddenly seized and shoved back against the coral. “Let go!”

“No,” the shark says, running his existing eye down Jason’s torso, “I don’t think I will.”

His eyes widen, and Jason shakes his head as more blood from his shoulder billows up around them, carried forward by the current. “No! No, get off me! Get off!” He tries to thrash, but the weight pinning him in place is too much. Almost effortlessly, the shark transfers his grip on both of Jason’s wrists to one hand, then slaps him across the face. “You fucker,” Jason gasps, feeling like his nose is broken.

“Settle,” the shark orders him, “I won, boy.” One corner of his lips rises in a smirk, and Jason fights not to flinch in the face of those teeth. “Over both of you. You know what that means.”

“Go suck a jellyfish!” Jason snaps, trying to cover for the sudden bolt of fear he feels. In the space of a minute, everything has gone wrong. The next step in his and Dick’s months long courtship of each other suddenly turned to sand by this new mer’s arrival. “I swear if you’ve killed him…”

He yelps as the shark bends his wrists back further, in a pointed gesture that’s an obvious punishment for the insult. “Relax,” the mer snorts, “He’s alive. Killing something that pretty would only be a waste.”

Jason twists his head to look at Dick again. The current has pushed him back against the reef, and a thin trail of blood drifts through the water from his head towards the surface. Jason swallows hard at the sight of it.

“You’ve got me,” he manages to get out, “Take what you want, but leave him out of this.”

The shark clicks his tongue in amusement, “Right of conquest doesn’t limit me to just one of you, boy. But it’s cute that you’re trying to protect him.” Jason shivers as a clawed finger runs down his cheek, “You smell fresh. Did he mate with you before I got here?”

“None of your business.” Jason hisses. Next to the chunk of his shoulder missing, the fresh bite mark Dick left on him when they had sex barely stings at all, and Jason knows the mark he left on Dick in turn will be just as obvious to any predatory eyes.

The shark twists his wrists again, and Jason shrieks as it tugs on his shoulder, causing a fresh plume of blood to rise up out of the wound. “Careful, pet. You don’t want to make me angry.”

“Or what, you’ll bite me? Just get on with it,” He groans, despite how in reality he wants this mer to do anything but that. “Take what you want and fuck off.”

His captor looks amused again. “What’s your name, boy?”

“None of your—ahh!” Jason gasps at the tug on his arm. He glares again, “... Jason. It’s Jason, all right?”

“Jason.” The shark repeats, drawing the syllables out like he’s tasting them. “My name is Slade. Now, I’ll ask you again; did he mate with you before I got here?”

Jason swallows as the flush returns to his face. He doesn’t know what greater harm it will do to answer, unlike what his continued silence will do, so gritting his teeth, he gives in and nods, “Yes.”

Slade’s eyes track downwards, and despite himself Jason can’t help but feel a small shiver of arousal.

For a mer, _any_ mer, power is attractive. Strength in its purest sense. Their culture, what they have of it, is built on that fact; both biologically and socially. When looking for a mate, strength is often the first thing considered, far more than looks or personality. It was the thing that initially attracted Jason to Dick, when their first encounter resulted in a battle that ended with the older mer putting him down like some untested hatchling. It was only after they’d finished fighting that he’d noticed how beautiful Dick was, and then — much later — how interesting, intelligent and playful. 

It’s the reason why mer courtship, at least for his and Dick’s species, can be so drawn out. First they prove strength, then the interested party announces their intention by giving gifts, before finally they test compatibility by hunting and living together. Sex too, sometimes, if it hasn’t already been taken by right of conquest. It’s only after that, if everything goes well, that the final seal of ‘Mate’ is applied to a relationship.

Jason swallows as the slow slide of Slade’s hand down his body draws him back out of his own mind. Of course, that pattern doesn’t ring true for all species of mer; sharks for one. They tend to be much more immediate with their interests. The most powerful always take what they want, no further questions or rituals needed.

“Good,” Jason hears him say. “This will be easier on you then.”

He gasps as two fingers suddenly spear into him, far bigger and longer than Dick’s. As they curve and prod and test his inner walls. Jason pulls against the grip on his wrist, but the rest of his body arches, an unexpected keen breaking free of his lips as instinct reacts in the face of his defeat. Slade dips his head down in the same moment, lapping his tongue over the raw bite on Jason’s neck, and by the depths, he hates how good that manages to feel.

There’s no question now what Slade wants from him.

“I’ve been watching you for a while now,” the shark purrs against his skin, “You and him both, dancing around each other. It was quite a show you put on.”

“What?” Jason replies, confused, before hissing at another strong press of Slade’s fingers inside him. “No… no, we would have noticed you. You couldn’t have.”

“I am very good at what I do, boy.” Slade answers, amused. “I wouldn’t have made it to this age if I wasn’t, and you two were too busy being wrapped up in one another to pay that much attention to your surroundings.”

Jason hisses again, this time in irritation rather than forced pleasure. “Fucking shark.”

“Yes, that's the idea.” Teeth graze his jaw. “You and your boy are such pretty, deadly little things, after all. Far too tempting to pass up.”

“Then why wait this long?” Jason groans, feeling himself growing hard enough for his cock to slide free of its sheath once again above Slade’s fingers. “If you’ve been watching us all this time, why not… ah!”

“To make sure you really were compatible with each other, of course.” Smiling smugly, Slade withdraws his hand. “I wouldn’t want to go claiming both of you if you were just going to end up fighting with each other all the time.”

He shivers, unable to help it, as Slade’s tail curls around his. Powerful, and so much larger; one simple twist of it feels heavy and inescapable, compressing his fins where it happens to fall across them. Even if he wasn’t hurt, Jason doesn’t think he could escape the coil of that tail. It’s… He really doesn’t want that to make his breath sharpen with anticipation, but it does.

There’s a little voice in the back of his head that sounds suspiciously like his dam, telling him that the best mate is strong, and skilled, and capable of defending against any threat.

Jason’s seen Dick chase off another mer before; just once. He thought Dick fit all those descriptors, but Slade… Jason hasn’t felt _small_ since he was still young, long before he met Dick, even before he grew into his adult colors.

"I'd suggest you relax," Slade says, pressing him back against the coral. "Little mers like you, you tend to squirm. I don't mind, but you might want to make this easy on yourself.”

He sees the way Slade curves his back just a little, recognizes it as the same way Dick curved, making enough room between them for his cock to slide free. Jason looks down without thinking about it, and his breath catches. It's fucking _big_. Too big for him to be remotely comfortable with it anywhere near him, and definitely not in him. No, no way. Maybe he's unwillingly attracted to the strength Slade represents, but that does not extend to wanting that thing interacting with him in any way.

A hand clasps around his throat, pinning his head back against the coral before he can do more than start to bare his teeth. He hisses anyway, the last free bit of his tail beating the water in useless struggle.

The flash of Slade's smile is as much amusement as threat. “You bite me, boy, and I'll break your jaw. That's not the part of you I want.”

It's all the warning he gets before Slade's pressing into him, big and hot and insistent, pressure forcing him open so much further than the fingers or Dick. He shrieks, partially from the sting of it but mostly from outrage. 

“You see,” Slade chuckles, the throatier bass of his tone the only clue to the pleasure he feels, “I warned you.”

“You bottom feeding… squid sucking... spawn of a jellyfish!” he tries to squirm away, but there’s nowhere to go. “When I get free, I’m going to feed you to a crab!”

“Mm, no, I don’t think you will.” Slade’s hand squeezes tighter around his neck as he leans his face in closer, treating Jason to a perfect view of his sharpened teeth. “Because when this is over, you’re going to have accepted me as your superior, boy. Your mate until I decide otherwise, and so will he.”

The strength of the grip is such that it presses down tight over Jason’s gills, restricting his ability to pull water through them and breathe. At the same time, Slade undulates his hips, sending brand new spikes of unwanted pain and pleasure sliding their way through him.

The end result is dizzying and, to everything Jason’s instincts tell him is right, also thrilling. He can’t utter any sound, or even really move. Gods curse him, he likes that. On a deep, indescribable level, he likes it, even as his mind continues to spit venom at Slade’s intrusion. For the sheer arrogance of him, thinking he can just come into their lives and take over like this.

His eyelids flutter as the lack of breath starts to get to him, only deeply ingrained instinct stopping him from trying to breathe through his mouth, as if he was above the water. But the urge grows, as he falls lax in Slade’s grip. Dizzy, slow…

The grip over his gills eases, and they flare suddenly wide as his body automatically sucks in enough of a breath to burn through the fog. Sensation whips back over Jason like the burn of hot water, and he screeches, hoarse and needy, at the realisation Slade is still fucking him.

The shark laughs at the sound. “Liked that, didn’t you, boy? Don’t worry, I have plenty more to give you where that came from; provided you give in and accept me.”

He punctuates the words with a particularly vicious thrust, prompting Jason to cry out again, and his own cock, neglected between them aside from the occasional press where it rubs against his stomach, throbs for attention. It would be so easy to do as Slade says and ask for relief from it, but he refuses. This mer is not the one he wants to mate with.

“Hm, stubborn.” Slade doesn’t sound displeased by his refusal. “We’ll see how long that lasts.”

The fingers around his throat start to clench down again, which is when an angry hiss cuts through the water around them.

“Get off him!”

Jason jolts at the sound of Dick’s voice, and then again when Slade hisses back, deeper and with a flash of sharp teeth.

"Easy, _boy_ ," Slade says, tone all but dripping with warning. His movement has stopped, but it leaves Slade's cock buried uncomfortably deep in him. The fingers on his neck spread far enough apart not to entirely block his gills, even as they tighten painfully. "Come any closer and I'll snap his neck."

Out of the corner of one eye, Jason can just see the flash of Dick's tail.

"You wouldn't. You want him."

Slade's teeth show in a smile, not remotely friendly. “Both of you. But just one is good enough.”

His fingers tighten even further, and twist to drag Jason’s head to the side. The pressure against his gills aches and _hurts_ , but he has nowhere to pull away to, nowhere to get away from the uncomfortable strain the angle is causing. His eyes squeeze shut, lips curling up to bare his teeth in helpless, desperate defiance.

“Jason!”

His eyes snap open, searching out Dick’s shape past the block of his own arm. Floating a distance away, the cut on his forehead still trailing a faint stream of blood up into the water. His teeth are bared, claws fully extended. Every bit the deadly suitor Jason’s been allowing near him, if it wasn’t for his wide, worried eyes.

“Well, boy?” Slade asks, still smirking, “What’s it going to be?”

Even at this awkward angle, Jason can see the way Dick hesitates. The uncertainty in his face as he tries to figure out what to do, and out of nowhere, a sudden flash of irritation floods through him. If only he hadn’t had to yell at Slade first, Dick could have snuck up on the shark while he was busy with Jason and killed him from behind. Then they wouldn’t be stuck at this impasse. Then he’d be free, and they could—

The sharp claws on Slade’s fingers cut into his neck, causing fresh blood to seep out. Against his will, Jason flinches, letting out a sharp cry of protest.

"Alright!" A sharp flick of Dick's tail propels him a little further away, palms lifting in surrender. "Okay, you win. Just don't hurt him."

"Oh, don't worry, boy. As long as you behave, I'll save all that for you." Slade's hand eases only slowly, but enough pressure stays to keep his head forced to the side. Not enough to hurt, now, but enough to keep Dick in his sights. "Now you stay there and watch, boy, and you think about what I'm going to do to you when it's your turn. You might want to be slick for that."

Dick doesn't get any chance to answer, as the next moment Slade begins to move again.

Jason arches at the sudden sensation, his back curving away from the coral pressed against it as the pressure inside him snaps back to the forefront of his awareness. Pleasure slices up through him like the sting of a ray, and it distracts him from Slade leaning close until he's only a breath away, teeth a fraction away from the ear turned upwards. The proximity makes him nervous, but he can barely hold onto that feeling, and the best he can manage is a choked, protesting sound.

"It's so useful when little mers like you care about each other," Slade says right into his ear, voice a rich murmur. "It doesn't mean anything, though. He might be dangerous, but just look at him. _Look_."

With his head turned how it is, Jason doesn't have much choice but to do just that.

Dick's claws are away, tail flicking restlessly but doing no more than stabilizing him against the currents. The concern is easy to read, but so is the wariness. He's afraid. Even if the very fact that he's staying there wasn't proof enough, the flicker of his gaze back and forth, from Jason to Slade, is obvious enough.

"He's weak, little mer. Afraid of me. He's lost once already." Slade's lips graze the very edge of his ear, voice falling into a sinister hiss. "He can't protect you. All he's going to do is float there and watch me take you, watch me spill in you just like he did. All that courting, and those promises, and when it counts they don't matter one bit. Don't you want someone with more power, Jason? Someone that can _actually_ keep you safe, and cared for?"

Even if he had words, the tightness of Slade's fingers on his throat would make saying them hard. That's not fair, though; Dick's protecting him by staying back, by keeping away until the threat to his life is done. Slade's threat.

But… He _lost_. Slade _won_. That's—

"Just ask," Slade says, thrusts growing a little harder. "Ask, boy, and I can give you all of it. All you have to do is give in; accept my victory."

Jason feels the shiver tear through him, shaking him from shoulders to the tip of his captured tail. "No," he just manages to choke out, his voice nearly as quiet as Slade's just because of the difficulty in speaking. "You're not—”

"Him? No, I'm better than him, boy. I can give you everything he only pretended to be capable of." Teeth scrape the shell of his ear, then his lobe, then just under his jaw. “I’ll even give you him, too. Be mine, and you can stay with him. Doesn’t that sound good, boy?”

Slade’s hand loosens and slips away from his throat, and teeth take their place, scraping across the side of his neck. Jason’s breath hitches, eyes squeezing shut for a second as he fights the urge to tilt his head back in surrender. He presses his face into his arm, bares his teeth as Slade’s tongue laps across the ache of his wounded shoulder, then the faint sting of Dick’s bite, just under the flutter of his gills on that side.

“What if I don’t?” he manages to grit out, opening his eyes and turning his head just enough to look up at Slade.

It gets him an amused curl of Slade’s mouth, and a blunt scrape of claws down his side from the free hand. Enough to make him shiver and bite back a pleased sound, though there’s no disguising how he tightens around the intrusion inside him. Gods below, but it feels good; the sting all but gone now, leaving nothing but the overwhelming stretch of it.

“Then I kill you,” Slade says, “or him. Or we do this as many times as it takes for you to accept me as stronger than either of you can manage. I have time, boy.”

He stares, and finds no lie. The thrill of it curls down through his stomach. His protest of, “This isn’t how we do things,” feels weak.

Slade’s hand slides around his back, resting at the small of it, just where his skin fades under scales. “What? You want me to court you? Bring you gifts? Prove my skill as a hunter?” A flash of a grin. “I’ve proven. If it’s gifts you want, boy, be mine and you’ll get them. I take care of what’s mine.”

He thinks he believes it.

He twists his wrists against Slade’s grip, and this time doesn’t fight the thrill the unyielding strength of it sends down into his gut. His chin lifts just a little, half an invitation, but he bares his teeth as he meets Slade’s gaze.

Jason means every word when he promises, “I’ll gut you if you don’t.”

Slade grins and leans in, and Jason lets his head fall back the last couple inches to let teeth close on the side of his neck, directly over the bite Dick left there. The hand on his back presses him closer, and _finally_ there’s pressure on his cock, caught between their stomachs with each roll of movement. He gasps, feels the prick of teeth slicing into his skin to leave a bloody, obvious mating mark around the much shallower scratches Dick left. Slade's hand, a moment later, shoves between their bodies and wraps around his cock, causing him to writhe and keen.

Past the reverberation of Slade growling into his throat, and the sensation of Slade driving more forcefully into him, he barely even hears Dick's protesting sound. Not enough of it registers to make him flinch, let alone stop. Couldn’t even if he wanted to, as a matter of fact, with the way Slade is all over him; rough palm dragging up and down Jason’s cock while his own is buried deep inside. His teeth stay locked into Jason’s neck as well, worrying the wound deep enough that it should scar even with their kind’s formidable healing abilities at work, and sending deep, blissful signals to the most primal parts of his brain.

There’s absolutely no way he can last long in the face of that.

Jason comes, bubbles issuing from his lips as he screams out his pleasure into the water, and try as he might not to, he can’t help but observe that this time it’s far more intense than it was with Dick. Though whether that’s because getting here took longer or Slade’s bigger, or any other factor, he can’t even begin to tell. All he knows is, it feels good, overwhelming, and when Slade himself finally, _finally_ , stills and spills inside him, letting his seed join what Dick left there earlier, that feeling only grows.

“See now,” the shark purrs as he withdraws his teeth from him, “All that fuss, and here you are, all blissful and fucked out. Bet it makes you wish you’d given in earlier, doesn’t it? Well, no matter, there’ll be plenty more of this for you in the future now, boy; I guarantee it.”

Jason blinks up at him. The flow of his blood into the water is so thick now, it’s actually obscuring his ability to see, but he can still make out the savage smirk occupying Slade’s features; the smug pleasure he obviously feels at having got his way.

“Bastard,” he manages, hissing as he feels the cock inside him start to retract, “Just… keep your promise.”

“Oh, I will,” Slade promises, finally releasing his hold on Jason’s wrists, as well as starting to unwind their tails. “You’ll see that shortly. But for now, I’m going to need you to be a good boy and stay there. The pretty one in blue there still needs to learn the same lesson, after all.”

Pulling his arms back down hurts. Both in his wounded shoulder and his neck. But Jason does it anyway, slowly pulling his tail close so he can curl up close to the reef behind him. He’s exhausted suddenly, and wants almost nothing more than to close his eyes and rest. Yet he can’t let himself, as watching Slade turn to advance on Dick — who is now snarling openly and flexing his claws again in warning — is beyond his ability to look away from.

He wants to shout to Dick not to fight, to just give in and accept Slade as he did, as the thought of him getting himself killed anyway after Jason gave into Slade partly to save his life is something he can scarcely abide. But after months of courtship, he also knows that such a thing would do no good. Dick will fight as long as he can fight — as long as he believes he still has a chance at winning. The only way he’ll stop is for Slade to prove himself to him, the same way he did to Jason.

Shuddering to himself at the thought, Jason curls up tighter against the reef, and waits, impatiently, for both his wounds to stop bleeding and Dick to be brought back over alongside him.

He hopes.

**Author's Note:**

> [Skali's tumblr](https://skalidra.tumblr.com/)
> 
> [Fire's tumblr](https://firefrightfic.tumblr.com/)


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